21045647390 has 8 divisors (see below), whose sum is σ = 37882165320. Its totient is φ = 8418258952.

The previous prime is 21045647387. The next prime is 21045647417. The reversal of 21045647390 is 9374654012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1052282360 + ... + 1052282379.

It is an arithmetic number, because the mean of its divisors is an integer number (4735270665).

Almost surely, 2^21045647390 is an apocalyptic number.

21045647390 is a deficient number, since it is larger than the sum of its proper divisors (16836517930).

21045647390 is a wasteful number, since it uses less digits than its factorization.

21045647390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2104564746.

The product of its (nonzero) digits is 181440, while the sum is 41.

The spelling of 21045647390 in words is "twenty-one billion, forty-five million, six hundred forty-seven thousand, three hundred ninety".